Hybrid drives or hybrid vehicles typically comprise two different kinds of drives or engines. Hybrid vehicles, in particular passenger cars, typically make use of the combination of a combustion engine and an electric motor. The combustion engine and the electric motor are selectively and alternately coupled to the wheels of the vehicle.
Typically, in a lower speed regime, as for instance in city traffic, the vehicle might be exclusively driven by means of the electric motor, whereas the combustion engine may be the drive of choice for driving the vehicle in a higher velocity range.
Depending on the actual driving speed, the electric motor or the combustion engine have to be alternately coupled and decoupled to the wheels or to the power train of the vehicle. If the vehicle is driven by the combustion engine and moves at a relatively high velocity, it is particularly beneficial to disconnect or to decouple the electric motor from the wheels and/or a respective power train. Otherwise, the electric motor due to its intrinsic RPM-limit tends act as a brake.
Further, the mechanical coupling of the electric motor and associated wheels is otherwise unnecessarily stressed. Respective gears may induce friction losses, e.g. due to oil splash. Also the inertia of various rotating parts may otherwise decrease the driving efficiency of the entire vehicle.
As soon as a vehicle is driven in a lower velocity range, in which the electric motor has to be coupled and connected to the vehicle's wheels and wherein the combustion engine may be entirely disconnected or decoupled from respective wheels, the mechanical coupling of a non-rotating electric motor to a rotating wheel is rather elaborate and complex.
When making use of a conventional friction clutch for coupling of the electric motor with a rotating vehicle wheel, the clutch mechanism will be subject to extreme stress and mechanical wear and may be therefore quite susceptible to failure. It may thus require intensive maintenance on a short-term time scale.
It is therefore at least one object to provide an improved coupling and synchronizing device for selectively coupling of an electric drive to at least one wheel axle of a vehicle. The coupling and synchronizing device should provide a fast and reliable coupling and connecting of the electric motor and wheel axle. At the same time, the coupling and synchronizing should be easy to assemble and inexpensive to manufacture. In addition, other objects, desirable features, and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.